London (AFP) - Jannik Sinner is on course for a blockbuster Wimbledon showdown with Novak Djokovic after the defending champion ended German veteran Jan-Lennard Struff’s fairytale run in the quarter-finals.

Sinner won 7-5, 7-6 (⁷⁄₄), 6-3 on Court One and will face Djokovic in the last four if the seven-time Wimbledon champion beats Canadian Felix Auger-Aliassime later on Tuesday.

In the women’s tournament, Coco Gauff and Karolina Muchova reached their first Wimbledon semi-finals.

With Wimbledon basking in sweltering temperatures this week, world number one Sinner had to answer some uncomfortable questions about his ability to withstand the heat.

The 24-year-old Italian wilted in the recent French Open when the mercury reached boiling point, sparking a stunning second-round defeat against Juan Manuel Cerundolo, who battled back from two sets and 5-1 down to beat Sinner.

Bidding to win Wimbledon for the second successive year, Sinner lived up to his claim that he would cope with the London heatwave against Struff – at 36 the oldest man to become a first-time quarter-finalist at the majors in the Open era.

The four-time Grand Slam champion wasn’t at his best, but his booming serve kept world number 74 Struff at bay as he reached his 10th Grand Slam semi-final and third at Wimbledon.

“It was a huge test today. I felt comfortable on the physical side, a good step forwards,” Sinner said.

“We worked a lot after Paris trying to understand what went wrong and prepared in the best possible way.”

Djokovic hopes to equal Roger Federer’s record of eight Wimbledon singles titles by winning a record 25th major.

That would make him the oldest man to win a Grand Slam in the Open era.

Victory for the 39-year-old Serb against third seeded Auger-Aliassime would take Djokovic into a record-extending 15th Wimbledon semi-final and 55th at the Grand Slams.

He would also reach the Wimbledon last four for an eighth consecutive time, setting a new record for the longest streak of men’s singles semi-final appearances at the All England Club.

- Gauff in uncharted territory -

The all-American encounter on Centre Court went Gauff’s way as the seventh seed beat fellow American Jessica Pegula 4-6, 6-3, 6-3.

Gauff – a two-time major champion – was appearing in the last eight at the All England Club for the first time.

The 22-year-old made a sluggish start as fourth seeded Pegula, 32, took the first set.

But Gauff hit back emphatically, seizing the momentum in the second set before sealing victory in the third.

Seven years after she became the youngest player to reach the Wimbledon main draw aged 15 and then stunned Venus Williams on her debut, Gauff is two wins away from an even more impressive feat at the All England Club.

She is into the semi-finals of a Grand Slam for the first time since winning her most recent major at the French Open last year.

She is the youngest player to appear in all four Grand Slam semi-finals since Maria Sharapova in 2007.

“Considering I hadn’t won a match in two years on grass before this tournament, I’m really happy with how I played today,” Gauff said.

In the last four, Gauff faces Czech 10th seed Muchova, who beat Japanese star Naomi Osaka 7-6 (⁷⁄₄), 6-4.

Muchova had never been past the first round in her four previous visits to Wimbledon, but she won the grass-court tournament at Bad Homburg in June.

“Oh my god, I was very nervous! I know you can’t lose focus because if you give her a little chance, she takes it,” Muchova said.

The 29-year-old lost her only Grand Slam final appearance against Iga Swiatek at the 2023 French Open.

French Open champion Alexander Zverev finished off his delayed last-16 tie against Jiri Lehecka, winning 6-4, 7-5, 3-6, 7-6 (⁸⁄₆) to book a quarter-final clash with American sixth seed Taylor Fritz.

Zverev had been leading by two sets when the match was halted by the 2200 GMT curfew on Monday.